Amino Acid
L-Lysine (Antiviral)
Also known as: L-lysine, Lysine monohydrochloride
Essential amino acid that inhibits herpes virus replication by competing with arginine.
Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.
Every L-Lysine (Antiviral) product we have scored
| # | Product | Score | Per serving |
|---|---|---|---|
| 1 | Pure Encapsulations L-Lysine | 94 A | $0.17 |
| 2 | BulkSupplements L-Lysine HCl Capsules | 92 A | $0.19 |
| 3 | Life Extension L-Lysine | 91 A | $0.09 |
| 4 | Solgar L-Lysine | 91 A | $0.14 |
| 5 | Nature Made L-Lysine 1000 mg Tablets | 90 A | $0.16 |
| 6 | Thorne MediClear-SGS™ - Vanilla | 86 A- | $2.10 |
| 7 | Vital Nutrients Lysine 500mg | 86 A- | $0.48 |
| 8 | Thorne Amino Complex - Travel Packs - Berry | 85 A- | $1.20 |
| 9 | Thorne Amino Complex - Travel Packs - Lemon | 85 A- | $1.20 |
| 10 | Thorne Amino Complex - Berry | 84 A- | $1.47 |
| 11 | Thorne Amino Complex - Lemon | 84 A- | $1.47 |
| 12 | Bluebonnet Nutrition L-LYSINE 500 mg | 83 A- | $0.28 |
Scored on dose accuracy, form, label transparency and third-party testing. Per-serving cost is list price divided by servings per container. No brand pays to be listed or ranked.
Common questions
How much L-Lysine (Antiviral) should I take?
The typical range is 1000-3000mg daily for prevention, up to 9g daily during outbreak. Ongoing for prevention, higher during outbreaks
When should I take L-Lysine (Antiviral)?
Divided doses, away from meals. Empty stomach if tolerated.
Which form of L-Lysine (Antiviral) is best?
Capsules — Common. Other forms in the catalog: Tablets, Powder, Topical.
Is L-Lysine (Antiviral) safe?
Commonly reported: GI upset, Diarrhea at high doses. Serious warnings: May increase cholesterol in some, High doses long-term may affect kidney. Caution with kidney disease at high doses
Which L-Lysine (Antiviral) supplement scores highest?
Pure Encapsulations L-Lysine, at 94/100. Scored on dose accuracy, form, label transparency and third-party testing — no brand pays to be listed or ranked.
Daily target & upper limit
1000 mg / dayL-Lysine (Antiviral) has an established daily reference intake. See best forms, label synonyms, upper-limit warnings, and top-scoring supplements:
L-Lysine (Antiviral) dosage reference →Primary uses
- Herpes prevention
- Cold sore treatment
- Shingles support
- Immune support
How it works
- Competes with arginine for viral replication
- Arginine needed for herpes reproduction
- Supports collagen synthesis
- May enhance calcium absorption
Dosage
- Typical range
- 1000-3000mg daily for prevention, up to 9g daily during outbreak
- Timing
- Divided doses, away from meals
- With food
- Empty stomach if tolerated
- Duration
- Ongoing for prevention, higher during outbreaks
- Special populations
- Those with herpes simplex or shingles history
Forms
- Capsules
- Tablets
- Powder
- Topical
Safety
Common side effects
- GI upset
- Diarrhea at high doses
Contraindications
- Lysinuric protein intolerance
Products containing L-Lysine (Antiviral)
Top-scoring supplements in our catalog that list L-Lysine (Antiviral) on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.
Evidence notes
Good evidence for herpes simplex prevention
Grade B: Some human trials support key claims; further confirmation needed.
Related in Amino Acid
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Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider. Individual needs and risks vary — consult a professional before starting, stopping, or combining supplements, especially if you are pregnant or nursing, taking medication, or managing a health condition.